Re: process killed: text file modification

[+freebsd-fs]


On 2017. 03. 09. 14:20, Gergely Czuczy wrote:
> On 2017. 03. 09. 11:27, Gergely Czuczy wrote:
>> Hello,
>>
>> I'm trying to build a few things from ports on an rpi3, the ports 
>> collection is mounted over NFS from another machine. When it's trying 
>> to build pkg i'm getting the error message in syslog:
>>
>> rpi3 kernel: pid 4451 (sh), uid 0, was killed: text file modification
>>
>> The report to pkg_at_:
>> https://lists.freebsd.org/pipermail/freebsd-pkg/2017-March/002048.html
>>
>> In ports-mgmt/pkg's config.log It fails at the following entry:
>> configure:3726: checking whether we are cross compiling
>> configure:3734: cc -o conftest -O2 -pipe  -Wno-error 
>> -fno-strict-aliasing   conftest.c  >&5
>> configure:3738: $? = 0
>> configure:3745: ./conftest
>> configure:3749: $? = 137
>> configure:3756: error: in `/usr/ports/ports-mgmt/pkg/work/pkg-1.10.0':
>> configure:3760: error: cannot run C compiled programs.
>> If you meant to cross compile, use `--host'.
>> See `config.log' for more details
>>
>> # uname -a
>> FreeBSD rpi3 12.0-CURRENT FreeBSD 12.0-CURRENT #0 r314949: Thu Mar 9 
>> 08:58:46 CET 2017 
>> aegir_at_marvin.harmless.hu:/tank/rpi3/crochet/work/obj/arm64.aarch64/tank/rpi3/src/sys/AEGIR 
>> arm64
> So far, a few additions:
> Time is synced between the NFS server and the client.
> it's an open() call which is getting the kill, and it's not the file 
> what's being opened, but the process executing it.
> Here's a simple code that reproduces it:
> #include <stdio.h>
>
> int main() {
>
>   FILE *f = fopen ("/bar", "w");
>
>   fclose(f);
>   return 0;
> }
>
> Conditions to reproduce it:
>  - The resulting binary must be executed from the nfs mount
>  - The binary must be built after mounting the NFS share.
>
> I haven't tried building it on a different host, I don't have access 
> to multiple RPis. Also, if I build the binary, umount/remount the NFS 
> mount point, which has the binary, execute it, then it works.
>
> I've also tried this with the raspbsd.org's image, I could reproduce 
> it as well.
>
> Another interesting thing is, when I first booted the RPi up, the NFS 
> server was a 10.2-STABLE, and later got updated to 11-STABLE. While it 
> was 10.2 I've tried to build some port, and I don't remember having 
> this issue.
>
> So, could someone please help me figure this out and fix it? This 
> stuff should work pretty much.
>
So, this error message comes from here:
https://svnweb.freebsd.org/base/head/sys/fs/nfsclient/nfs_clbio.c?revision=314436&view=markup#l1674

It's the NFS_TIMESPEC_COMPARE(&np->n_mtime, &np->n_vattr.na_mtime) 
comparision that fails, np should be the NFS node structure, from the 
vnode's v_data, and n_vattr is the attribute cache. As I've seen these 
two are being updated together, so I don't really see by the code why 
they might differ. Could someone please take a look at it, with more 
experience in the NFS code? -czg